Earpiece Charging Case Detection

ABSTRACT

A system with an earpiece that comprises a rechargeable earpiece power source and a case that is configured to interface with the earpiece in an earpiece power source charging configuration and comprises a case power source that is configured to recharge the earpiece power source. A detection circuit, located in part in the earpiece and in part in the case, includes at least one earpiece electrical contact that is configured to electrically couple to at least one case electrical contact when the earpiece is interfaced with the case in the earpiece power source charging configuration. The detection circuit is configured to detect, using the earpiece and case electrical contacts, whether the earpiece is interfaced with the case in the earpiece power source charging configuration, even if one of the earpiece power source and the case power source does not have power.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of and claims priority to applicationSer. No. 16/905,666 filed on Jun. 18, 2020.

BACKGROUND

This disclosure relates to detecting when an earpiece is in its chargingcase.

Wearable audio devices, including earpieces such as earbuds and hearingaids, typically have rechargeable batteries. The carrying case for thewearable audio devices can also recharge the batteries of the wearableaudio devices when the wearable audio devices are placed into the case.

SUMMARY

All examples and features mentioned below can be combined in anytechnically possible way.

In one aspect, a system includes an earpiece that comprises arechargeable earpiece power source, and a case that is configured tointerface with the earpiece in an earpiece power source chargingconfiguration and comprises a case power source that is configured torecharge the earpiece power source. A detection circuit, located in partin the earpiece and in part in the case, comprises at least one earpieceelectrical contact that is configured to electrically couple to at leastone case electrical contact when the earpiece is interfaced with thecase in the earpiece power source charging configuration. The detectioncircuit is configured to detect, using the earpiece and case electricalcontacts, whether the earpiece is interfaced with the case in theearpiece power source charging configuration, even if one of theearpiece power source and the case power source does not have power.

Some examples include one of the above and/or below features, or anycombination thereof In an example the earpiece is configured to belocated in an ear of a user. In an example the earpiece comprises ahearing aid. In an example the case is configured to contain theearpiece in a substantially closed case interior volume. In an examplethe detection circuit comprises a first voltage divider in the case anda second voltage divider in the earpiece.

Some examples include one of the above and/or below features, or anycombination thereof. In some examples the detection circuit comprisescircuitry in the earpiece that is configured to detect when the earpieceis interfaced with the case in the earpiece power source chargingconfiguration. In an example the earpiece further comprises circuitrythat is configured to disable predetermined earpiece functionality afterthe detection circuitry in the earpiece detects when the earpiece isinterfaced with the case in the earpiece power source chargingconfiguration. In an example the circuitry in the earpiece that isconfigured to detect when the earpiece is interfaced with the case inthe earpiece power source charging configuration comprises circuitry fordetecting when a sensed voltage of the earpiece changes due toconnection of the case power source to the earpiece. In an example thecircuitry in the earpiece for detecting when a sensed voltage of theearpiece changes due to connection of the case power source to theearpiece comprises a voltage divider with an input that is electricallyconnected to the earpiece power source and with an output, wherein whenthe case power source is electrically connected to the voltage divider apath through the voltage divider is altered, and the voltage divideroutput is thereby altered.

Some examples include one of the above and/or below features, or anycombination thereof. In some examples the detection circuit comprisescircuitry in the case that is configured to detect when the earpiece isinterfaced with the case in the earpiece power source chargingconfiguration. In an example the circuitry in the case that isconfigured to detect when the earpiece is interfaced with the case inthe earpiece power source charging configuration is configured toconnect the case power source to the earpiece to cause a change in stateof an earpiece circuit element, wherein the circuitry in the case isconfigured to detect the change in state of the earpiece circuit elementas an indication that the earpiece is interfaced with the case in theearpiece power source charging configuration. In an example thedetection circuitry further comprises a variable voltage source in theearpiece that is configured to receive power from the case power source.In an example the detection circuitry further comprises circuitry in thecase and the earpiece that together accomplish a boost converter, andwherein operation of circuitry in the case is altered by the boostconverter and such alteration is used as an indication that the earpieceis interfaced with the case in the earpiece power source chargingconfiguration.

Some examples include one of the above and/or below features, or anycombination thereof. In an example circuitry in the case is configuredto provide power from the case power source that is used to both powerthe circuitry in the earpiece that is configured to detect when theearpiece is interfaced with the case in the earpiece power sourcecharging configuration, and to recharge the earpiece power source. In anexample the detection circuit comprises at least four sets of contactscomprising at least four external contacts on the earpiece that areconfigured to electrically connect with at least four contacts inside ofthe case. In an example a first set of contacts electrically connectsground potentials of the case and the earpiece, a second set of contactselectrically connects the case power source to the earpiece powersource, a third set of contacts is used by the earpiece circuitry todetermine when the earpiece is interfaced with the case in the earpiecepower source charging configuration, and a fourth set of contacts isused by the case circuitry to determine when the earpiece is interfacedwith the case in the earpiece power source charging configuration. In anexample the detection circuit comprises two sets of contacts, wherein afirst set of contacts electrically connects ground potentials of thecase and the earpiece, and a second set of contacts is configured to beused by the case circuitry to determine that the earpiece is interfacedwith the case in the earpiece power source charging configuration.

In another aspect, a system includes a hearing aid that is configured tobe located in an ear of a user and comprises a rechargeable hearing aidpower source, and a case that is configured to interface with thehearing aid in a hearing aid power source charging configuration whereinthe hearing aid is contained in a substantially closed volume of thecase. The case comprises a case power source that is configured torecharge the hearing aid power source. A detection circuit, located inpart in the hearing aid and in part in the case, comprises at least fourexternal hearing aid electrical contacts that are configured toelectrically couple to at least four electrical contacts inside of thecase when the case is interfaced with the hearing aid in the hearing aidpower source charging configuration. The detection circuit is configuredto detect, using the hearing aid and case electrical contacts, whetherthe hearing aid is interfaced with the case in the hearing aid powersource charging configuration, even if one of the hearing aid powersource and the case power source does not have power. A first set ofcontacts electrically connects ground potentials of the case and thehearing aid, a second set of contacts electrically connects the casepower source to the hearing aid power source, a third set of contacts isused by the hearing aid circuitry to determine when the hearing aid isinterfaced with the case in the hearing aid power source chargingconfiguration, and a fourth set of contacts is used by the casecircuitry to determine when the hearing aid is interfaced with the casein the hearing aid power source charging configuration. The detectioncircuit comprises circuitry in the hearing aid that is configured todetect when the hearing aid is interfaced with the case in the hearingaid power source charging configuration, and circuitry in the case thatis configured to detect when the hearing aid is interfaced with the casein the hearing aid power source charging configuration by connecting thecase power source to the hearing aid to cause a change in state of ahearing aid circuit element and detecting the change in state of thehearing aid circuit element as an indication that the hearing aid isinterfaced with the case in the earpiece power source chargingconfiguration. The hearing aid further comprises circuitry that isconfigured to disable predetermined hearing aid functionality after thedetection circuitry in the hearing aid detects when the hearing aid isinterfaced with the case in the hearing aid power source chargingconfiguration.

In another aspect, a system includes a hearing aid that is configured tobe located in an ear of a user and comprises a rechargeable hearing aidpower source, and a case that is configured to interface with thehearing aid in a hearing aid power source charging configuration whereinthe hearing aid is contained in a substantially closed volume of thecase. The case comprises a case power source that is configured torecharge the hearing aid power source. A detection circuit, located inpart in the hearing aid and in part in the case, comprises at leastthree external hearing aid electrical contacts that are configured toelectrically couple to at least three electrical contacts inside of thecase when the case is interfaced with the hearing aid in the hearing aidpower source charging configuration. The detection circuit is configuredto detect, using the hearing aid and case electrical contacts, whetherthe hearing aid is interfaced with the case in the hearing aid powersource charging configuration, even if one of the hearing aid powersource and the case power source does not have power. A first set ofcontacts electrically connects ground potentials of the case and thehearing aid, a second set of contacts electrically connects the casepower source to the hearing aid power source, and a third set ofcontacts is used to determine when the hearing aid is interfaced withthe case in the hearing aid power source charging configuration. Thedetection circuit comprises a first voltage divider in the case, and asecond voltage divider in the hearing aid that has an input that iselectrically connected to the hearing aid power source and has anoutput. When the case power source is electrically connected to thesecond voltage divider a path through the voltage divider is altered,and the voltage divider output is thereby altered. The hearing aidfurther comprises circuitry that is configured to disable predeterminedhearing aid functionality after the detection circuitry in the hearingaid detects when the hearing aid is interfaced with the case in thehearing aid power source charging configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an earpiece and a charging case for theearpiece.

FIG. 2 is a schematic diagram of two earpieces located inside of a casein the earpiece power source charging configuration.

FIG. 3A is a block diagram of a hearing aid and a charging case for thehearing aid, illustrating a detection circuit that is configured todetect whether the hearing aid is interfaced with the case in thehearing aid charging configuration, even if one of the hearing aid powersource and the case power source does not have power.

FIG. 3B is a variant of the hearing aid and charging case of FIG. 3A.

FIG. 4 is a block diagram of a hearing aid and a charging case for thehearing aid, illustrating another detection circuit that is configuredto detect whether the hearing aid is interfaced with the case in thehearing aid charging configuration, even if one of the hearing aid powersource and the case power source does not have power.

FIG. 5 is a block diagram of a hearing aid and a charging case for thehearing aid, illustrating another detection circuit that is configuredto detect whether the hearing aid is interfaced with the case in thehearing aid charging configuration, even if one of the hearing aid powersource and the case power source does not have power.

DETAILED DESCRIPTION

Wearable audio devices, such as earbuds, hearing aids, and other typesof earpieces, usually have a rechargeable battery. A case that isconfigured to store the earpieces can also be configured to recharge theearpiece batteries when the earpieces are stored in the case. Knowledgeof when the earpieces are properly engaged in or docked in a chargingcase can be used to advantage. For example, if the earpiece is on whenit is docked, it can be turned off. In the case of hearing aids, if thehearing aids are not turned off when they are in the charging case theycan begin to feedback and squeal, which is obviously undesirable.Knowledge of when the earpieces are properly docked in a charging casecan also be used to set a user interface (UI) to indicate the dockingstatus and/or charge state, and/or make intelligent decisions on howpower is used when the earpiece is fully charged but still docked. Otheractions based on proper docking are known in the technical field. Insome docking status knowledge schemes, if the power source in the earbudor the power source in the case does not have power when the earpiece isdocked in the case, the docking status may not be properly determined.

In the present disclosure a system and method for detecting when anearpiece is properly docked with a case includes a detection circuitthat is located in part in the earpiece and in part in the case. In anexample the detection circuit includes at least one earpiece electricalcontact that is configured to electrically couple to at least one caseelectrical contact when the earpiece is interfaced with the case in theearpiece power source charging configuration. The detection circuit isconfigured to detect, using the earpiece and case electrical contacts,whether the earpiece is interfaced with the case in the earpiece powersource charging configuration, even if one of the earpiece power sourceand the case power source does not have power. Several exemplarydetection schemes are disclosed herein. These detection schemes areexemplary not limiting of the scope of the disclosure, as those skilledin the technical field could accomplish the detection in other ways.

This disclosure relates to a wearable audio device. Some non-limitingexamples of this disclosure describe a type of wearable audio devicethat is known as an earpiece, which can be, for example, an earbud or ahearing aid. Earbuds and hearing aids generally include one or moreelectro-acoustic transducers for producing sound and/or sensing sound.Earbuds and hearing aids can be wireless or wired. In examples describedherein they include a power supply (generally, a rechargeable battery),circuitry involved in recharging the power supply, and any necessaryprocessing. Other aspects of earbuds, hearing aids, and other types ofwearable audio devices that are not involved in this disclosure are notshown or described, simply for the sake of ease of illustration andclarity.

Some examples of this disclosure also describe a type of wearable audiodevice that is known as an open audio device. Open audio devices haveone or more electro-acoustic transducers (audio drivers) that arelocated off of the ear canal opening. In some examples the open audiodevices also include one or more microphones; the microphones can beused to pick up the user's voice, ambient sounds, and/or for noisecancellation. Open audio devices are further described in U.S. Pat. No.10,397,681, the entire disclosure of which is incorporated herein byreference for all purposes.

A headphone refers to a device that typically fits around, on, or in anear and that radiates acoustic energy directly or indirectly into theear canal. Headphones are sometimes referred to as earphones, earpieces,headsets, earbuds, or sport headphones, and can be wired or wireless. Aheadphone includes an electro-acoustic transducer (driver) to transduceelectrical audio signals to acoustic energy. The acoustic driver may ormay not be housed in an earcup or in a housing that is configured to belocated on the head or on the ear, or to be inserted directly into theuser's ear canal. A headphone may be a single stand-alone unit or one ofa pair of headphones (each including at least one acoustic driver), onefor each ear. A headphone may be connected mechanically to anotherheadphone, for example by a headband and/or by leads that conduct audiosignals to an acoustic driver in the headphone. A headphone may includecomponents for wirelessly receiving audio signals. A headphone mayinclude other functionality, such as additional microphones for anactive noise reduction system, or one or more microphones that are usedto pick up the user's voice and/or ambient sounds.

An open audio device includes but is not limited to an off-earheadphone, i.e., a device that has one or more electro-acoustictransducers that are coupled to the head or ear (typically by a supportstructure) but do not occlude the ear canal opening. In some examples anopen audio device is an off-ear headphone comprising audio eyeglasses,but that is not a limitation of the disclosure as in an open audiodevice the device is configured to deliver sound to one or both ears ofthe wearer where there are typically no ear cups and no ear buds. Thewearable audio systems contemplated herein may include a variety ofdevices that include an over-the-ear hook, such as a wireless headset,hearing aid, eyeglasses, a protective hard hat, and other open ear audiodevices.

One or more of the devices, systems, and methods described herein, invarious examples and combinations, may be used in a wide variety ofwearable audio devices or systems, including wearable audio devices invarious form factors.

It should be noted that although specific implementations of wearableaudio devices primarily serving the purpose of acoustically outputtingaudio are presented with some degree of detail, such presentations ofspecific implementations are intended to facilitate understandingthrough provisions of examples and should not be taken as limitingeither the scope of the disclosure or the scope of the claim coverage.

FIG. 1 is a block diagram of a detection system 10 that includes anearpiece 14 and a charging case 12 for the earpiece. System 10 can alsobe used to accomplish methods described herein. System 10 is configuredto detect when earpiece 14 is properly docked with a case 12. System 10includes a detection circuit with detection circuit part or portion 26located in earpiece 14 and detection circuit part or portion 25 locatedin case 12. Both earpiece 14 and case 12 include electrical contactsthat are configured, located, and arranged to be electrically coupledtogether when the earpiece is properly engaged with (docked with) thecase. Each of the earpiece and case can have one or more such contacts.In this non-limiting example each has four mating contacts—contacts15-18 on or in case 12, and contacts 19-22 that are exposed to thesurface of earpiece 14 such that they make electrical contact withcontacts 15-18, respectively, when the earpiece is properly engage withor interfaced with the case in an earpiece power source chargingconfiguration. In this example the detection circuit includes at leastone earpiece electrical contact that is configured to electricallycouple to at least one case electrical contact when the case isinterfaced with the earpiece in the earpiece power source chargingconfiguration. The detection circuit comprising portions 25 and 26 isconfigured to detect, using the earpiece and case electrical contacts,whether the earpiece is interfaced with the case in the earpiece powersource charging configuration, even if one of the earpiece power source24 and the case power source 23 does not have power. Earpiece 14 alsoincludes one or more transducers 28, such as microphone(s) and/oracoustic drivers. One or both types of transducers are commonly used inearpieces. For example, a driver can be used to create sound that isoutputted into the ear or into the environment close to the ear. Amicrophone can be used to detect the user's voice and/or environmentalsounds. When the earpiece is an earbud or a type of open audio device,microphones are often used to detect the user's voice (e.g., for phonecalls or voice commands) and/or to detect sound from the acoustic driverand/or environmental sounds for use in active noise reduction. When theearpiece is a hearing aid, microphone(s) can be used to detectenvironmental sound that is reproduced by the audio driver and providedinto or close to the user's ear. It should be understood that aspects ofearpieces and charging cases for earpieces are not included in FIG. 1simply for the sake of clarity.

FIG. 2 is a schematic diagram of two earpieces 40 and 42 inside ofcharging case 30. Earpieces 40 and 42 are in the earpiece power sourcecharging configuration. Case 30 comprises bottom portion 32 and topportion 34 connected by hinge 36 so that top 34 can be opened andclosed. Some of the case interior 38 is open. The case interior 38 thusacts as a sound chamber. If one or both earpieces are turned on anddetecting and producing sound when they are in the case, the sound canfeedback, leading to undesirable squealing. It is thus best for theearpieces to be automatically turned off when they are placed in thecase. Detection of the earpiece(s) being properly located in thecharging configuration can also be used to control other aspects of thecase and/or earpieces. For example, as described above knowledge of whenthe earpieces are properly docked in a charging case can be used toadvantage. For example, if the earpiece is on when it is docked, it canbe turned off. Also, a UI (not shown) can be set to indicate the dockingstatus and/or charge state, and/or make intelligent decisions on howpower is used when the earpiece is fully charged but still docked. Otheractions based on proper docking are known in the technical field.

FIG. 3A is a block diagram of a system 50 that includes a hearing aid 54and a charging case 52 for the hearing aid, illustrating a detectioncircuit that is configured to detect whether the hearing aid/earpiece isinterfaced with the case in the charging configuration, even if one ofthe hearing aid/earpiece power source and the case power source does nothave power. Hearing aid 54 has external contacts 60-63 that areconfigured to electrically connect to case electrical contacts 56-59,respectively, when the earpiece is properly docked in the case. Oncedocked, case power source 74 (which can be a battery or a power sourcethat is supplied with AC or mains power, e.g., from a wall outlet)supplies power to recharge earpiece battery power source 88 via contacts58 and 62. Aspects of the detection circuit that are configured todetect whether hearing aid 54 is properly docked with case 52 areillustrated in FIG. 3A. Such detection can occur even if one of casepower source 74 and hearing aid power source 88 does not have power. Alikely but non-limiting scenario is when the hearing aid battery diesand it is put into the case to charge. Also, the case may not be pluggedinto a power supply for the case power source (which is often +5V DC).

In many existing earpiece charging cases, if the earpiece battery isdepleted when the earpiece is placed into the case the battery will haveto partially recharge before the earpiece and case can communicate thatthe earpiece is docked. This can lead to undesired actions such as thosedescribed above. Also, if the case is not powered (e.g. it is eitherunplugged or the battery is drained) but the hearing aid still has powerand is on, since the hearing aid cannot detect the case the hearing aidmay not be shut off automatically, and when the case is shut the hearingaid can produce undesired and annoying squealing sounds. Anotherconsequence is that the hearing aid will drain its battery when it couldhave otherwise been preserving the battery for later use.

The detection circuit includes two general purpose input/output (GPIO)pins 81 and 83 with pullup resistors 82 and 84, and I2C functionality80, all of which can be enabled by appropriate digital and analoghardware and any necessary control and communications functionality(e.g., firmware), which can be parts of a system on an I2C chip. In anexample I2C processor 80, resistors 82 and 84, and processor 86 are allfunctional aspects of one hearing aid processor. Pin 81 is connected tocontact 60 and pin 83 is connected to contact 61. Ground is provided viamating contacts 59 and 63. Contact 60 is used by case 52 to sense theconnection of hearing aid 54 via processor 70 and resistor 72; whenpower source 74 is coupled to the hearing aid via contacts 58 and 62,processor 86 and I2C 80 enable pullup of pin 81. The resulting change involtage at pin 56 is sensed by processor 70 as an indication that casepower is being provided to hearing aid 54 (i.e., hearing aid 54 is inthe proper docking position). Processor 70 can cause desired actions ofcase 52, such as turning on “charging” indicator LEDs (not shown). Also,connection causes pin 83 to be pulled up. The resulting change involtage at pin 83 (due to the power from hearing aid power source 88 anda ground connection via case contact 58) allows processor 86 of hearingaid 54 to determine that the hearing aid is docked and take desireactions of the hearing aid, such as shutting off its transducers (notshown in this drawing) to prevent squealing. A corollary aspect of thissystem design is that the hearing aid I2C chip can disable the GPIOpullups in order to allow for better communication between the hearingaid and case. Logic in the processor can determine if a state change onthe I2C pins is an I2C message or a static state. It can then disablethe GPIO pullups until its logic determines that the I2C transaction islikely over.

A variant of system 50 is illustrated as system 50 a, FIG. 3B. Hearingaid 54 a includes processor 86 a that functionally includes I2C 80 a andGPIO 83 a. Hearing aid 54 a detects case 52 a in the same manner asdescribed above relative to FIG. 3A. Case 52 a senses hearing aid 54 aby detecting the voltage on pin 56 using processor 70. When the hearingaid is disconnected, this voltage is normally high. Plugging in thehearing aid will pull this line low, but only if contacts 56, 58, and 59are all properly connected to the corresponding hearing aid contacts.The application of the case power source 74 on contact 62 turns on theN-channel MOSFET 89, which connects the signal at contact 60 to ground.For the scenario where the charging case does not have power, it doesnot turn on transistor 89, which does not matter since the case does nothave power to sense the signal at contact 56. Resistor 73 is connectedto the case rail voltage. Accordingly, if processor 70 detects a highvoltage, either the hearing aid is not connected, or one of contacts 56,58, and 59 is not making proper connection. If processor 70 detects alow voltage, then contacts 56, 58, and 59 are all connected properly tothe corresponding contacts of the hearing aid.

FIG. 4 is a block diagram of a system 100 that includes a hearing aidand a charging case for the hearing aid, illustrating another detectioncircuit that is configured to detect whether the hearing aid isinterfaced with the case in the hearing aid charging configuration, evenif one of the hearing aid power source and the case power source doesnot have power. System 100 employs three mating contacts on each of case102 and hearing aid 104, contacts 103-105 and 106-108, respectively.Contact set 105 and 108 establishes a ground connection. Contact set 104and 107 establishes a power connection that can both recharge hearingaid power source 150 and provide power to the hearing aid detectioncircuit if hearing aid power source 150 is depleted. Contact set 103 and106 establishes a sense connection. Case 102 includes voltage comparator110 and hearing aid 104 includes voltage comparator 140. Each comparatorincludes an input voltage (Vrail, provided by the local power source).The comparators also include resistors R1-R4 and back-to-back P-FETS 114and 144.

The sense pin is shared and allows either part to detect the other,regardless of whether the other has power. In a comparator method, theresistor values are chosen so that the voltages fall regardless ofwhether the hearing aid has power. Depending on the resistor values, thecircuitry can be established such that Vsense on the case side risesabove a high threshold when a powered hearing aid is connected and fallsbelow a lower threshold when an unpowered hearing aid is connected. Thevoltage swing is at least in part dependent on the resistor values.

With N-channel MOSFET 146 that is connected to case power source 120,the detection works only if the sense pins, power pins, and ground pinsare all connected. If MOSFET 146 is not present the system is configuredto detect presence on the sense pin before turning on the power to thehearing aid, whereas including it requires the power to be turned on inorder to detect.

The enable voltages (Ven, both for the case and the hearing aid) comefrom the respective system processors/controllers 112 and 142. Theenable voltage on each side needs to be low enough to turn on theP-channel MOSFETs of sets 114 and 144. They could even be tied lowstatically since the PFETs would turn off if the Vrail was not present.Disabling the PFETs could save a little power, especially if otherinformation in the system can be used to establish that the detection isnot needed. Non-limiting examples of other information that can be usedto establish that detection is not needed include the following. Thecharging case has a lid that can be opened and closed. The caseprocessor can sense whether the lid is open or closed. If the processordetermines that the lid is closed and the hearing aids are not inserted,then it can assume that it is not possible for the hearing aids to beinserted until the lid is opened. Until the lid is opened, the hearingaid detection portion can be disabled. On the hearing aid side, if thehearing aid has detected via its processor that it is connected to acase and it can also sense that the case is supplying power, it candisable the detection circuit until the case power supply is removed. Atthis point it can reenable the detection circuit to double check whetherit is still inserted in the case. Doing this does not impact thecharging case's ability to sense that the hearing is attached. Thehearing aid detection circuit can be pulsed on and off while the hearingaid is in normal operation. As long as the period at which the sensingis pulsed is frequent enough, the hearing aid would detect the case andmute its output before a user would notice any of the describedundesirable behaviors. However, the default value would be for theenable signals to be low so that the gate-to-source voltage is bigenough to enable the detection circuit.

Connection and power options relating to system 100 are as follows. Ifboth case 102 and hearing aid 104 are powered and are successfullyconnected on all pins, each senses the other and performs theirrespective post-sensing tasks via processors 112 and 142 (e.g., the caseupdates its UI, the hearing aid mutes its output). If the case ispowered and the hearing aid is unpowered, and they are successfullyconnected on all three pins, the case can sense that the hearing aid ispresent and updates its UI (e.g., an LED display), and the hearing aidbegins charging. If the case is unpowered and the hearing aid is poweredand they are successfully connected on all pins the case cannot chargethe hearing aid but the hearing aid will sense the case presence andmodify its own configuration as needed. If both the case and the hearingaid are powered but the power pins are not connected and the other twosets of pins are connected the hearing aid could sense that it isconnected, but the case would not sense any connection.

The case will sense the hearing aid as follows. The voltage on theVsense (case) node will swing when a hearing aid is plugged in. Thischange in voltage could be sensed in several different ways. One is bythe use of a comparator (which compares it against some predefinedreference voltage). Two comparators can be used as depicted in FIG. 4,to catch both the rising and falling scenarios. Another is by readingthe voltage with an analog to digital converter and deciding in firmwareif the threshold has been crossed. This method could be used in one orboth of the hearing aid and the case. Another is that the Vsense (case)voltage could also be used to control a transistor (not shown). Thetransistor could be used as a switch, and the Vsense (case) voltagecould be conditioned so that it would cross the turn-on threshold forthe transistor when the hearing aid is connected/disconnected

FIG. 5 is a block diagram of a system 180 that includes a hearing aid184 and a charging case 182 for the hearing aid, illustrating anotherdetection circuit that is configured such that the case can detectwhether the hearing aid is interfaced with the case in the hearing aidcharging configuration, even if one of the hearing aid power source andthe case power source does not have power. Another sensor (not shown,such as a Hall effect sensor in the hearing aid and a mating magnet inthe case) could be used for the hearing aid to sense the case. System180 requires only two sets of mating contacts. Set 186 and 188 establishground connections, and contacts 185 and 187 are the power/sensecontacts that when connected connect case power source 194 to rechargehearing aid power source 196, and also provide power to operate thedetection circuitry of the hearing aid. Detection works using a pulsevoltage source 202 and boost converter circuitry split between thehearing aid and case, 192 and 190, respectively. The boost converterwill eventually turn on digital switch 200 thus changing the voltage atlocation 197, indicating to case processor 198 that the hearing aid isconnected. Hearing aid processor 204 can be used to both control pulsesource 202 and, using a separate sensor, determine that the hearing aidis connected to the case and take appropriate actions as describedelsewhere herein.

Elements of figures are shown and described as discrete elements in ablock diagram. These may be implemented as one or more of analogcircuitry or digital circuitry. Alternatively, or additionally, they maybe implemented with one or more microprocessors executing softwareinstructions. The software instructions can include digital signalprocessing instructions. Operations may be performed by analog circuitryor by a microprocessor executing software that performs the equivalentof the analog operation. Signal lines may be implemented as discreteanalog or digital signal lines, as a discrete digital signal line withappropriate signal processing that is able to process separate signals,and/or as elements of a wireless communication system.

When processes are represented or implied in the block diagram, thesteps may be performed by one element or a plurality of elements. Thesteps may be performed together or at different times. The elements thatperform the activities may be physically the same or proximate oneanother, or may be physically separate. One element may perform theactions of more than one block. Audio signals may be encoded or not, andmay be transmitted in either digital or analog form. Conventional audiosignal processing equipment and operations are in some cases omittedfrom the drawing.

Examples of the systems, devices, and methods described herein comprisecomputer components and computer-implemented steps that will be apparentto those skilled in the art. For example, it should be understood by oneof skill in the art that the computer-implemented steps may be stored ascomputer-executable instructions on a computer-readable medium such as,for example, floppy disks, hard disks, optical disks, Flash ROMS,nonvolatile ROM, and RAM. Furthermore, it should be understood by one ofskill in the art that the computer-executable instructions may beexecuted on a variety of processors such as, for example,microprocessors, digital signal processors, gate arrays, etc. For easeof exposition, not every step or element of the systems and methodsdescribed above is described herein as part of a computer system, butthose skilled in the art will recognize that each step or element mayhave a corresponding computer system or software component. Suchcomputer system and/or software components are therefore enabled bydescribing their corresponding steps or elements (that is, theirfunctionality), and are within the scope of the disclosure.

A number of implementations have been described. Nevertheless, it willbe understood that additional modifications may be made withoutdeparting from the scope of the inventive concepts described herein,and, accordingly, other examples are within the scope of the followingclaims.

What is claimed is:
 1. A system, comprising: an earpiece that comprisesthree separate earpiece external electrical contacts and a rechargeableearpiece power source; a case that is configured to interface with theearpiece in an earpiece power source charging configuration andcomprises three separate case external electrical contacts and a casepower source that is configured to recharge the earpiece power source;wherein each of the three separate earpiece external electrical contactsis configured to electrically couple to a respective one of the threeseparate case electrical contacts when the earpiece is interfaced withthe case in the earpiece power source charging configuration; wherein afirst pair of coupled earpiece and case electrical contacts areconfigured to pass power from the case power source to the earpiecepower source; and wherein the electrical interconnection of a secondpair of coupled earpiece and case electrical contacts is used by thecase to sense connection of the earpiece to the case and the electricalinterconnection of a third pair of coupled earpiece and case electricalcontacts is used by the earpiece to sense connection of the earpiece tothe case.
 2. The system of claim 1 wherein the earpiece is configured tobe located in an ear of a user.
 3. The system of claim 1 wherein theearpiece comprises a hearing aid.
 4. The system of claim 1 wherein thecase is configured to contain the earpiece in a substantially closedcase interior volume.
 5. The system of claim 1 wherein the earpiecefurther comprises circuitry that is configured to disable predeterminedearpiece functionality after the earpiece senses connection of theearpiece to the case.
 6. The system of claim 1 wherein the earpiecefurther comprises circuitry for detecting when a sensed voltage of theearpiece changes due to connection of the case power source to theearpiece.
 7. The system of claim 6 wherein the circuitry in the earpiecefor detecting when a sensed voltage of the earpiece changes due toconnection of the case power source to the earpiece comprises a voltagedivider with an input that is electrically connected to the earpiecepower source and with an output, wherein when the case power source iselectrically connected to the voltage divider a path through the voltagedivider is altered, and the voltage divider output is thereby altered.8. The system of claim 1 wherein the case further comprises a firstvoltage divider and the earpiece further comprises a second voltagedivider, and wherein the first and second voltage dividers are used tosense connection of the earpiece to the case.
 9. The system of claim 1wherein the case further comprises circuitry that is configured toconnect the case power source to the earpiece to cause a change in stateof an earpiece circuit element, wherein the circuitry in the case isconfigured to detect the change in state of the earpiece circuit elementas an indication that the earpiece is interfaced with the case in theearpiece power source charging configuration.
 10. The system of claim 9wherein the earpiece further comprises a variable voltage source that isconfigured to receive power from the case power source.
 11. The systemof claim 1 further comprising circuitry in the case and the earpiecethat together accomplish a boost converter, and wherein operation ofcircuitry in the case is altered by the boost converter and suchalteration is used as an indication that the earpiece is interfaced withthe case in the earpiece power source charging configuration.
 12. Thesystem of claim 1 wherein circuitry in the case is configured to providepower from the case power source that is used to both power circuitry inthe earpiece that is configured to detect when the earpiece isinterfaced with the case in the earpiece power source chargingconfiguration, and to recharge the earpiece power source.
 13. The systemof claim 1 wherein the earpiece and the case each further comprises afourth external electrical contact that are configured to electricallycouple when the earpiece is interfaced with the case in the earpiecepower source charging configuration.
 14. The system of claim 13 whereinthe fourth set of contacts electrically connects ground potentials ofthe case and the earpiece.
 15. A system, comprising: a hearing aid thatis configured to be located in an ear of a user and comprises fourseparate hearing aid external electrical contacts and a rechargeablehearing aid power source; a case that is configured to interface withthe hearing aid in a hearing aid power source charging configurationwherein the hearing aid is contained in a substantially closed volume ofthe case, wherein the case comprises four separate case externalelectrical contacts and a case power source that is configured torecharge the hearing aid power source; wherein each of the four separatehearing aid external electrical contacts is configured to electricallycouple to a respective one of the four separate case electrical contactswhen the hearing aid is interfaced with the case in the hearing aidpower source charging configuration; wherein a first pair of coupledhearing aid and case electrical contacts are configured to pass powerfrom the case power source to the hearing aid power source; wherein asecond pair of coupled hearing aid and case electrical contacts areconfigured to electrically connect ground potentials of the case and thehearing aid; wherein the electrical interconnection of a third pair ofcoupled hearing aid and case electrical contacts is used by the case tosense connection of the hearing aid to the case and the electricalinterconnection of a fourth pair of coupled hearing aid and caseelectrical contacts is used by the hearing aid to sense connection ofthe hearing aid to the case; and wherein the hearing aid furthercomprises circuitry that is configured to disable predetermined hearingaid functionality after the hearing aid senses connection of the hearingaid to the case.